1. Field of the Invention
The invention relates to a device for determining the position of a scraper, which is displaceable for transport of coating material, in particular a liquid or powder lacquer, in a supply path of the coating material, with (a) a sensor responding to the presence of the scraper, and (b) a circuit arrangement to which the output signal of the sensor is supplied and which generates an electric output signal which is representative of the presence or absence of the scraper on the sensor.
2. Background Art
In coating techniques it is widespread to convey the coating material with the aid of a scraper through a hose, e.g. from a supply source to a different location, in particular to application devices. The movement of the scraper, in particular its arrival at the various scraper stations, is monitored with the aid of devices of the kind initially mentioned. Their output signal can then be used for controlling valves, for switching voltages, or suchlike. As sensors, both those which operate inductively or optically and those which respond to the magnetic field of a magnetic material entrained by the scraper can be considered.
In the known devices for determining the position of a scraper currently found on the market, in general the sensor is connected to the control circuit via an electric line. This is possible all the time the sensor is not located at high electric potential. The latter is the case, for example, in scraper stations assigned to application devices operating with internal charging, e.g. high rotation atomising.